Age-related macular degeneration (AMD) is the leading cause of blindness in the United States and most western countries. The Comparison of AMD Treatment Trials (CATT) is a set of large-scale, randomized clinical trials designed to evaluate the relative efficacy and safety of alternative treatments for the neovascular form of the disease that accounts for approximately 90% of blindness due to AMD. The goal of the Coordinating Center is to contribute to the success of the CATT by providing study leadership, data management, data analysis, and communication, by facilitating the execution of the study protocol, and by coordinating the activities of the study group. The Coordinating Center provides expertise on design of multicenter clinical trials, implementation and maintenance of high quality data management systems, statistical analysis, and quality assurance in data management and clinical center performance. The specific aims of the Coordinating Center to fulfill this role are: Work with the other members of the study group to further refine the study design;Create and maintain the study database through design of data collection forms, data capture, data editing, and data management; Provide timely, regular reports concerning study progress and performance to the clinical sites, OCT Reading Center, Fundus Photograph Reading Center, Executive Committee and its subcommittees, and the Data and Safety Monitoring Committee;Design and implement a full program of quality assurance activities, in conjunction with the Executive Committee;Provide interim and final statistical analysis of the accumulated data on primary and secondary outcomes, as well as ancillary studies; Contribute to and distribute support materials for all CATT meetings; Maintain an up-to-date assessment of the status of treatments for AMD that are under development;Participate and lead in the preparation of scientific presentations and reports. Administer subcontracts with CATT clinical centers and work with the Center for Medicare and Medicaid Services to provide clinical centers with reimbursement for patient care;The CATT will identify the best treatments for "wet" age-related macular degeneration, the leading cause of blindness in Americans. The Coordinating Center works to make sure the clinical trials are successful.